Various microphone assemblies in the art disclose how a diaphragm and a back-plate of a condenser transducer element can be coupled to an input stage of a preamplifier having a P-type field effect transistor. Examples of such references are EP 0969695 A1 and EP 1355416 A1.
In both EP 0969695 A1 and EP 1355416 A1, the respective diaphragms and the back-plates are coupled to the respective P-type field effect transistors between respective gate inputs of the transistors and ground. A disadvantage of this coupling or electrical interface is that noise applied or injected at the source input is amplified because ground acts as a signal reference terminal. The amplification of noise introduces unwanted disturbances in the desired audio signal provided by the condenser transducer element.
Thus, there is a need for an improved electrical coupling between a condenser transducer element and a P-type field effect transistor.